NASA APOLLO 17 MISSION (1972)
South Massif (2, 300 m - 75, 46ft)
The Moon
1. In Astronaut Harrison Schmitt next to a large boulder in the Taurus–Littrow valley on the Apollo 17 mission . The South massif is visible to the right. Original NASA caption. 1972
2. In South Massif - North facing slope of South Massif, with the 3.6 km diameter Ching-Te crater in the background, Original NASA caption, 1972
South Massif (2, 300 m - 75, 46ft) is, according to lunar standards, a relatively modest mountain, but with a rich history (geologic and exploration). South Massif is located at the edge of the Serenitatis impact basin on the Moon's nearside and borders the Taurus Littrow Valley where the Apollo 17 astronauts landed and explored.
The oblique view (n°2 above) dramatically shows the north-facing slope of South Massif, with the 3.6 km diameter Ching-Te crater in the background. From summit to base, the massif's relief exceeds that of the Grand Canyon.
The distinct high reflectance deposit that spreads across the Taurus Littrow valley floor formed as a giant landslide from the north face of South Massif. Apollo era scientists proposed that the landslide was caused by ejecta from Tycho crater landing on the summit and south side of the massif. The resulting seismic jolt sent regolith sliding down the steep north slope resulting in the distinctive landslide we see today. Look closely at the summit, you can see what appears to be dark and blocky material that may be a deposit of now solidifed impact melt from the Tycho event. Sampling the landslide was an objective of the Apollo 17 mission. By determining how long rocks had sat on the surface of the slide scientists could know the timing of the formation of Tycho crater, which is more than 2000 kilometers to the southwest.
As it turns out, the exposure ages of the samples brought back from the landslide were about 110 million years - thus Tycho crater was assigned that age. However, new mapping and analysis of the area brought forward a second hypotheisis, reported this spring at the 49th Lunar and Planetary Science Conference. The alternative idea is that the landslide was caused by motion along the Lee Lincoln fault. It is certainly logical that seismic shaking along such a massive fault could cause a landslide. In fact, the paper (authored by Apollo 17 astronaut Harrison Schmitt) proposes that there were actually two large quakes and thus two landslides, the younger covering most of the older. The older deposit (smaller lobe on the right) is distinguished by its lower reflectance relative to the brighter younger slide (left side). If Dr. Schmitt is correct then we do not know the age of Tycho crater which in turn has implications for how scientists estimate the ages of other young craters across the Moon (and other inner Solar System bodies).
The mission
Apollo 17 was the final mission of NASA's Apollo program.
Launched at 12:33 a.m. Eastern Standard Time (EST) on December 7, 1972, with a crew made up of Commander Eugene Cernan, Command Module Pilot Ronald Evans, and Lunar Module Pilot Harrison Schmitt, it was the last use of Apollo hardware for its original purpose; after Apollo 17, extra Apollo spacecraft were used in the Skylab and Apollo–Soyuz programs.
Apollo 17 was the first night launch of a U.S. human spaceflight and the final manned launch of a Saturn V rocket. It was a "J-type mission" which included three days on the lunar surface, extended scientific capability, and the third Lunar Roving Vehicle (LRV). While Evans remained in lunar orbit in the Command/Service Module (CSM), Cernan and Schmitt spent just over three days on the Moon in the Taurus–Littrow valley and completed three moonwalks, taking lunar samples and deploying scientific instruments. Evans took scientific measurements and photographs from orbit using a Scientific Instruments Module mounted in the Service Module.
The landing site was chosen with the primary objectives of Apollo 17 in mind: to sample lunar highland material older than the impact that formed Mare Imbrium, and investigate the possibility of relatively new volcanic activity in the same area. Cernan, Evans and Schmitt returned to Earth on December 19 after a 12-day mission.
Apollo 17 is the most recent manned Moon landing and the most recent time humans travelled beyond low Earth orbit. It was also the first mission to have no one on board who had been a test pilot; X-15 test pilot Joe Engle lost the lunar module pilot assignment to Schmitt, a scientist.
The mission broke several records: the longest moon landing, longest total extravehicular activities (moonwalks), largest lunar sample, and longest time in lunar orbit.
Astronaut Eugene A. Cernan, commander, makes a short checkout of the Lunar Roving Vehicle (LRV) during the early part of the first Apollo 17 Extravehicular Activity (EVA-1) at the Taurus-Littrow landing site.
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2019 - Wandering Vertexes...
by Francis Rousseau
